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<font face="Times New Roman">*** nb. Those of you developing
software in support of CMIP5 may need to modify things to include
one more CMIP5 experiment. See below:<br>
<br>
Dear all,<br>
<br>
At the WGCM meeting in Exeter there was agreement that the
"historical" runs should be extended from their official ending
date at the end of 2006 to about year 2012. The concentrations
and land-use changes specified in these runs will not be the same
for all groups and may not even be based on true observations (but
instead be estimated in various ways). Since these runs should
not be confused with the "historical" runs where everyone uses the
same forcing (based on observations), the feeling is these short
runs (2006-2012) should be labeled as a new experiment. I've sent
a message to the modeling groups describing what they should do.
</font><font face="Times New Roman">You might want to read items 6e
and 6f in that message (copied below). </font><font face="Times
New Roman">To accommodate these new runs, we need to add a line to
the second table of Appendix 1.1 of the DRS document with the
following entries:<br>
<br>
7.4 historicalExt historical extension</font>
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e<span style="font-size: 10pt; font-family: "Times New
Roman"; color: black;">xtension of
the historical simulation (experiment 3.2) through year 2012.</span>
<br>
<font face="Times New Roman"><br>
I understand this will require additions to much of the software,
possibly including CMOR2 tables, ESG publisher?, ESG node
software?, METAFOR questionnaire, ESG search?, etc.<br>
<br>
I apologize for these late changes, but the WGCM thought it
important to include these extensions of the historical runs so
that detection attribution studies could be done.<br>
<br>
Please pass on this message to anyone who might need to know this
(beyond those already on the GO-ESSP-tech mail list).<br>
<br>
Best regards,<br>
Karl<br>
<br>
---------------------------<br>
</font>
<div class="moz-text-html" lang="x-western"> <font face="Times New
Roman">Dear all,<br>
<br>
Here are some items that should be of interest to those of you
participating in CMIP5. Please pass on this information,
especially to those who are responsible for preparing the model
output for the CMIP5 archive.<br>
</font><font face="Times New Roman"><br>
1. </font>For those of you doing the emissions-driven
simulations: Unless it's too late, it is recommended that the
recently produced gridded fossil fuel emissions data from Andres
(hosted by IPSL) and the the land use data from Houghton (hosted
at MPI) should be used for the historical simulations. More
information should appear soon on the CMIP5 website. <br>
<br>
These fossil fuel emissions data can be retrieved from:<br>
<a class="moz-txt-link-freetext"
href="http://*dods.ipsl.jussieu.fr/cpipsl/ANDRES/">http://dods.ipsl.jussieu.fr/cpipsl/ANDRES/</a><br>
File name is :
CMIP5_gridcar_CO2_emissions_fossil_fuel_Andres_1751-2007_monthly_SC_mask11.nc<br>
It is a monthly dataset, units are gC/m2/s<br>
Also provided is an ascii file that contains the globally
integrated emissions for every month.<br>
CMIP5_gridcar_CO2_emissions_fossil_fuel_Andres_1751-2007_monthly_SC_grid1x1.txt
<br>
<br>
The land use file can be found at MPI:<br>
<a class="moz-txt-link-freetext"
href="http://*www.*mpimet.mpg.de/en/wissenschaft/land-im-erdsystem/wechselwirkung-klima-biogeosphaere/landcover-change-emission-data.html">http://www.mpimet.mpg.de/en/wissenschaft/land-im-erdsystem/wechselwirkung-klima-biogeosphaere/landcover-change-emission-data.html</a><br>
File name is:<span class="download">
carbon_emissions_landuse_20person.nc</span> <br>
It is an annual dataset, units are also gC/m2/s<br>
<font face="Times New Roman"><br>
2. </font>Again for those of you with coupled carbon climate
models (ESM's): The CMIP5 expts. 5.4 and 5.5 are designed to
isolate the climate change effects on carbon uptake from the
uptake due to CO2 concentration increases (in the absence of
climate change). Originally there were two options proposed for
these experiments: analyze 1%/yr CO2 increase runs or analyze
historical+RCP4.5 runs. At the WGCM meeting last month and in
subsequent discussion, it was decided that for groups who have not
yet performed these experiments, it would be better if they would
base these runs on the idealized 1%/yr CO2 increase (rather than
the historical+RCP4.5 simulations). <font face="Times New Roman">There
will, of course, also be interest in the historical+RCP4.5 runs,
so groups who have already done these runs, should contribute
them to the archive.</font><br>
<br>
<font face="Times New Roman">3. We recently posted a revised
document describing the model output requirements for CMIP5 (see
<a class="moz-txt-link-freetext"
href="http://cmip-pcmdi.llnl.gov/cmip5/output_req.html?submenuheader=2#metadata">http://cmip-pcmdi.llnl.gov/cmip5/output_req.html?submenuheader=2#metadata</a>
). </font><font face="Times New Roman">(Those of you who have
chosen *not* to use CMOR2 to rewrite your model output should
study this document carefully; those of you using CMOR may refer
to the CMOR documentation for most of the information you need
to know. The</font><font face="Times New Roman"> CMOR
documentation has also been recently revised with expanded
descriptions of what you must supply.)</font> <font
face="Times New Roman">At the beginning of the output
requirements document there is a link directing the user to the
bottom of the document where a list of the changes that were
made can be found. Nearly all the changes were simply to
improve clarity. Please note, however, that a new global
attribute is now required for most simulations
(parent_experiment_rip), which identifies which ensemble member
the child experiments was spawned from. This information will
be essential for many CMIP5 studies.</font><font face="Times New
Roman"><br>
<br>
4. The so-called "data reference syntax" document has also been
revised. Again, many of the changes should simply make it
easier to understand. Data providers will be especially
interested in the official "short names" of the CMIP5
experiments, since these names are used in constructing
filenames. This document can be obtained through the following
link: <a class="moz-txt-link-freetext"
href="http://cmip-pcmdi.llnl.gov/cmip5/output_req.html?submenuheader=2#req_format">http://cmip-pcmdi.llnl.gov/cmip5/output_req.html?submenuheader=2#req_format</a><br>
<br>
5. The latest version of CMOR2 was just released on 12 November
2010. The changes made were summarized on an announcement made
to those of you on the cmor email list. It also includes the
latest "requested variables" CMOR tables (also posted at <a
href="http://cmip-pcmdi.llnl.gov/cmip5/output_req.html?submenuheader=2#req_list">http://cmip-pcmdi.llnl.gov/cmip5/output_req.html?submenuheader=2#req_list</a>
), which includes a number of formerly missing "standard
names", and also some corrections. Please download the latest
version of CMOR, the CMOR tables and the documentation before
continuing to process your data.<br>
</font><br>
6. At the WGCM meeting there was agreement that it would be
useful for model evaluation and detection/attribution studies to
extend the CMIP5 historical runs to near-present (as we have for
AMIP), rather than ending them in 2005. In fact since the CMIP5
project is ongoing, it would be useful to have simulations
extended to at least the end of 2012 using some estimate of recent
and future forcing. There is, however, no community-wide accepted
observationally-based concentration/emissions past 2005. Groups
are therefore free to use whatever concentrations, solar forcing,
SO2 emissions etc. they want to use in extending these runs. It
is also o.k. for detection/attribution studies to simply splice
one of the RCP runs to the end of the historical simulations. No
matter what forcing is chosen it is important to consider the
following:<br>
<br>
a) The groups should take care that there are no substantial
discontinuities in the forcing in passing <span
class="moz-txt-citetags"></span>from the "past" to the "future",
defined to be the end of 2005. <br>
<br>
b) It is recommended that if an ensemble of "all-forcings"
historical <span class="moz-txt-citetags"></span>simulations have
been run, then <b class="moz-txt-star"><span class="moz-txt-tag">*</span>each<span
class="moz-txt-tag">*</span></b> member of the ensemble should
<span class="moz-txt-citetags"></span>be carried to the end of
2012. Thus, a full ensemble of runs (through year <span
class="moz-txt-citetags"></span>2012) would be available for
analysis.<br>
<br>
c) It is recommended that all historical runs with only a subset
of forcing (<span class="moz-txt-citetags"></span>e.g., GHG only,
natural forcing only) should also be extended through the year
2012.<br>
<br>
d) If one of the RCP forcings is used to extend the historical
run, it may not matter too much which RCP is chosen, and CMIP5
makes no strong recommendation. If a modeling group has no
preference, they might choose the RCP8.5 expt., as at least one
group (the Hadley Centre) has made this choice already.<br>
<br>
e) For all-forcing (anthro + natural) historical runs, the
extended portions of these runs should be treated as a new runs
spawned from the parent historical runs at the end of year 2005.
If this run is forced by an RCP that extends at least to the end
of the 21st century, then nothing special needs to be done. If,
however, some other forcing is used or if the run is an RCP run
that is truncated after a few years (say ending in 2012), then the
run should be considered a "historical extension" experiment with
its output placed in a directory named historicalExt. The
"forcing" attribute (a netCDF global attribute) should describe
what forcing is used to extend the run, and this information will
also need to be recorded when entering information about the run
in the METAFOR questionnaire. Placing the extended portion of
the historical runs in a separate place will help guard against
users assuming that these runs are necessarily based on
historically-measured concentrations, land-use changes, solar
forcing, etc. For these historicalExt experiments, the ensemble
member (designated by the "rip" value appearing in the filename
and recorded as netCDF global attributes) will be identical to the
historical run it extends. Also for the runs, the identifying
netCDF global attributes should be defined as follows:
experiment="historical extension" and
experiment_id="historicalExt". The "Data Reference Syntax"
document and the CMOR tables will be revised shortly to include
these "new" experiments. <br>
<br>
f) If one chooses to do historical runs with only a subset of
forcing (e.g., GHG only, natural forcing only, single-forcing
experiments, etc.), then all the data for the complete historical
period and in the extended portion (from 2006-2012) would be kept
together, no matter what forcing was used (in the historicalNat,
historicalGHG, or historicalMisc directories). (In these clearly
"unrealistic" cases, naive users will be less likely to access the
output and possibly misuse it.) <br>
<br>
7. For your information, We've posted (see <a
href="http://cmip-pcmdi.llnl.gov/cmip5/terms.html?submenuheader=3">http://cmip-pcmdi.llnl.gov/cmip5/terms.html?submenuheader=3</a>
) the latest (and final) version of the the two different terms of
use governing the CMIP5 model output. It looks like about half
the groups plan to release their data for "unrestricted" use and
half for "non-commercial educational and research purposes" only.
<br>
<font face="Times New Roman"><br>
Carry on!<br>
<br>
Best regards,<br>
your faithful CMIP5 comrades (Karl's lame attempt to try to
develop a little esprit de corps here),<br>
Karl and Ron</font> </div>
<br>
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